package com.zrf.base.knowledge.sign;


import org.apache.commons.codec.binary.Hex;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.interfaces.ECPrivateKey;
import java.security.interfaces.ECPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;

public class Ecdsa {
    private static String src = "我是签名内容" ;
    public static void main(String []args){
        jdkECDSA();
    }
    public static void jdkECDSA(){
        // 1.初始化密钥
        try{
            KeyPairGenerator keyPairGenerator = KeyPairGenerator.getInstance("EC","BC");
            keyPairGenerator.initialize(256);
            KeyPair keyPair = keyPairGenerator.generateKeyPair() ;
            ECPublicKey ecPublicKey = (ECPublicKey)keyPair.getPublic() ;
            ECPrivateKey ecPrivateKey = (ECPrivateKey)keyPair.getPrivate() ;
            // 执行签名
            PKCS8EncodedKeySpec pkcs8EncodedKeySpec = new PKCS8EncodedKeySpec(ecPrivateKey.getEncoded());
            KeyFactory keyFactory = KeyFactory.getInstance("EC") ;
            PrivateKey privateKey = keyFactory.generatePrivate(pkcs8EncodedKeySpec) ;
            Signature signature = Signature.getInstance("SHA256withECDSA");
            signature.initSign(privateKey);
            signature.update(src.getBytes());
            byte []arr = signature.sign();

            System.out.println(Hex.encodeHex(arr));
            System.out.println(Hex.encodeHex(ecPublicKey.getEncoded()));
            // 验证签名
            X509EncodedKeySpec x509EncodedKeySpec = new X509EncodedKeySpec(ecPublicKey.getEncoded());
            keyFactory = KeyFactory.getInstance("EC");
            PublicKey publicKey = keyFactory.generatePublic(x509EncodedKeySpec);
            signature = Signature.getInstance("SHA256withECDSA");
            signature.initVerify(publicKey);
            signature.update(src.getBytes());
            boolean bool = signature.verify(arr);
            System.out.println("jdk ecdsa verify:"+bool);
        }catch(Exception e){

        }
    }
}